Assessment of Rainfall and Temperature Trends in Ballari District of Karnataka, India

Abstract

Climate change has emerged as a major global concern, leading to substantial alterations in temperature and precipitation patterns across different regions. This study investigates the spatial and temporal trends of rainfall and temperature in Ballari District, Karnataka, India, using gridded rainfall and temperature data obtained from the Indian Meteorological Department (IMD) for the period 1981–2025. The study provides a comprehensive assessment of long-term climate variability at monthly, seasonal, and annual scales in a semi-arid region that is highly vulnerable to climatic fluctuations. Variations in rainfall and temperature were analyzed using descriptive statistical techniques and the non-parametric Mann–Kendall (MK) trend test. The results indicated that the mean annual rainfall of the district was 855.25 mm, ranging from a minimum of 496.61 mm to a maximum of 1460.11 mm during the study period. Most monthly rainfall series exhibited weak to moderate trends; however, the post-monsoon season showed a statistically significant increasing trend (τ = 0.213, p = 0.049). Annual rainfall also demonstrated a weak positive trend (τ = 0.108, p = 0.319), although the trend was not statistically significant. Analysis of temperature trends revealed a significant increase in maximum temperature (Tmax) during January, August, November, December, the post-monsoon season, and at the annual scale. Similarly, minimum temperature (Tmin) exhibited significant increasing trends during August and annually. Overall, Tmax showed more pronounced and consistent increasing trends compared to Tmin throughout the study period. The findings highlight the increasing influence of climate variability and warming in Ballari District and provide valuable scientific evidence for climate-resilient agricultural planning, sustainable water resource management, and adaptation policy formulation in semi-arid regions facing future climate change challenges.